Glaucoma stent for treating glaucoma and methods of use

ABSTRACT

Surgical methods and related medical devices for treating glaucoma are disclosed. The method comprises trabecular bypass surgery, which involves bypassing diseased trabecular meshwork with the use of a stent implant. The stent implant is inserted into an opening created in the trabecular meshwork by a piercing member that is slidably advanceable through the lumen of the stent implant for supporting the implant insertion. The stent implant is positioned through the trabecular meshwork so that an inlet end of the stent implant is exposed to the anterior chamber of the eye and an outlet end is positioned into fluid collection channels at about an exterior surface of the trabecular meshwork or up to the level of aqueous veins.

RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/315,463, filed Aug. 28, 2001, entitled “GLAUCOMASHUNT FOR AB INTERNO USE” and U.S. Provisional Application No.60/363,980, filed Mar. 14, 2002, entitled “MEANS AND PROCEDURES FORIMPLANTING A GLAUCOMA SHUNT AB INTERNO”, the entirety of each one ofwhich is hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The invention generally relates to improved medical devices andmethods for the reduction of elevated pressure in organs of the humanbody. More particularly, the invention relates to the treatment ofglaucoma by trabecular bypass surgery, which is a means for using animplant or stent, such as a micro stent, shunt or the like, to bypassdiseased trabecular meshwork at the level of trabecular meshwork anduse/restore existing outflow pathways.

[0004] 2. Description of the Related Art

[0005] About two percent of people in the United States have glaucoma.Glaucoma is a group of eye diseases that causes pathological changes inthe optic disk and corresponding visual field loss resulting inblindness if untreated. Intraocular pressure elevation is the majoretiologic factor in all glaucomas.

[0006] In glaucomas associated with an elevation in eye pressure thesource of resistance to outflow is in the trabecular meshwork. Thetissue of the trabecular meshwork allows the “aqueous” to enterSchlemm's canal, which then empties into aqueous collector channels inthe posterior wall of Scblemm's canal and then into aqueous veins. Theaqueous or aqueous humor is a transparent liquid that fills the regionbetween the cornea at the front of the eye and the lens. The aqueoushumor is constantly secreted by the ciliary body around the lens, sothere is a continuous flow of the aqueous humor from the ciliary body tothe eye's front chamber.

[0007] The eye's pressure is determined by a balance between theproduction of aqueous and its exit through the trabecular meshwork(major route) or via uveal scleral outflow (minor route). The trabecularmeshwork is located between the outer rim of the iris and the internalperiphery of the cornea. The portion of the trabecular meshwork adjacentto Schlemm's canal causes most of the resistance to aqueous outflow(juxtacanilicular meshwork).

[0008] Glaucoma is grossly classified into two categories: closed-angleglaucoma and open-angle glaucoma. Closed-angle glaucoma is caused byclosure of the anterior angle by contact between the iris and the innersurface of the trabecular meshwork. Closure of this anatomical angleprevents normal drainage of aqueous humor from the anterior chamber ofthe eye.

[0009] Open-angle glaucoma is any glaucoma in which the angle of theanterior chamber remains open, but the exit of aqueous through thetrabecular meshwork is diminished. The exact cause for diminishedfiltration is unknown for most cases of openangle glaucoma. However,there are secondary open-angle glaucomas that may include edema orswelling of the trabecular spaces (from steroid use), abnormal pigmentdispersion, or diseases such as hyperthyroidism that produce vascularcongestion.

[0010] All current therapies for glaucoma are directed at decreasingintraocular pressure. This is initially by medical therapy with drops orpills that reduce the production of aqueous humor or increase theoutflow of aqueous. However, these various drug therapies for glaucomaare sometimes associated with significant side effects, such asheadache, blurred vision, allergic reactions, death from cardiopulmonarycomplications and potential interactions with other drugs. When the drugtherapy fails, surgical therapy is used.

[0011] Surgical therapy for open-angle glaucoma utilizes laser(trabeculoplasty), trabeculectomy and aqueous shunting implants afterfailure of trabeculectomy or if trabeculectomy is unlikely to succeed.Trabeculectomy is a major surgery that is most widely used and isaugmented with topically applied anticancer drugs such as 5-flurouracilor mitomycin-c to decrease scarring and increase surgical success.

[0012] Approximately 100,000 trabeculectomies are performed on Medicareage patients per year in the United States. This number would increaseif the morbidity associated with trabeculectomy could be decreased. Thecurrent morbidity associated with trabeculectomy includes failure (about10-15%), infection (a life long risk of about 2-5%), choroidalhemorrhage (about 1%, a severe internal hemorrhage from pressure too lowresulting in visual loss), cataract formation, and hypotony maculopathy(potentially reversible visual loss from pressure too low).

[0013] If it were possible to bypass the local resistance to outflow ofaqueous at the point of the resistance and use existing outflowmechanisms, surgical morbidity would greatly decrease. The reason forthis is that the episcleral aqueous veins have a backpressure that wouldprevent the eye pressure from going too low. This would substantiallyeliminate the risk of hypotony maculopathy and choroidal hemorrhage.Furthermore, visual recovery would be very rapid and risk of infectionwould be very small (a reduction from about 2-5% to about 0.05%).Because of these reasons surgeons have tried for decades to develop aworkable surgery for the trabecular meshwork.

[0014] The previous techniques, which have been tried, aregoniotomy/trabeculotomy, and other mechanical disruption of thetrabecular meshwork, such as trabeculopuncture, goniophotoablation,laser trabecular ablation and goniocurretage. These are brieflydescribed below.

[0015] Goniotomy/Trabeculotomy: Goniotomy and trabeculotomy are simpleand directed techniques of microsurgical dissection with mechanicaldisruption of the trabecular meshwork. These initially had earlyfavorable responses in the treatment of open-angle glaucoma. However,long-term review of surgical results showed only limited success inadults. In retrospect, these procedures probably failed secondary torepair mechanisms and a process of “filling in”. The filling in is theresult of a healing process which has the detrimental effect ofcollapsing and closing in of the created opening throughout thetrabecular meshwork. Once the created openings close, the pressurebuilds back up and the surgery fails.

[0016] Trabeculopuncture: Q-switched Neodymiun (Nd):YAG lasers also havebeen investigated as an optically invasive technique for creatingfull-thickness holes in trabecular meshwork. However, the relativelysmall hole created by this trabeculopuncture technique exhibits afilling in effect and fails.

[0017] Goniophotoablation/Laser Trabecular Ablation: Goniophotoablationis disclosed by Berlin in U.S. Pat. No. 4,846,172, and describes the useof an excimer laser to treat glaucoma by ablating the trabecularmeshwork. This was not demonstrated by clinical trial to succeed. Hillet al. used an Erbium:YAG laser to create full thickness holes throughtrabecular meshwork (Hill et al., Lasers in Surgery and Medicine11:341-346, 1991). This technique was investigated in a primate modeland a limited human clinical trial at the University of California,Irvine. Although morbidity was zero in both trials, success rates didnot warrant further human trials. Failure again was from filling in ofcreated defects in trabecular meshwork by repair mechanisms. Neither ofthese is a valid surgical technique for the treatment of glaucoma.

[0018] Goniocurretage: This is an ab-interno (from the inside)mechanical disruptive technique. This uses an instrument similar to acyclodialysis spatula with a microcurrette at the tip. Initial resultsare similar to trabeculotomy that fails secondary to repair mechanismsand a process of filling in.

[0019] Although trabeculectomy is the most commonly performed filteringsurgery, Viscocanulostomy (VC) and non-penetrating trabeculectomy (NPT)are two new variations of filtering surgery. These are ab-externo (fromthe outside), major ocular procedures in which Schlemm's canal issurgically exposed by making a large and very deep scleral flap. In theVC procedure, Schlemm's canal is cannulated and a viscoelastic druginjected (which dilates Schlemm's canal and the aqueous collectorchannels). In the NPT procedure, the inner wall of Schlemm's canal isstripped off after surgically exposing the canal.

[0020] Trabeculectomy, VC, and NPT are performed under a conjunctivaland scleral flap, such that the aqueous humor is drained onto thesurface of the eye or into the tissues located within the lateral wallof the eye. Normal physiological outflows are not used. These surgicaloperations are major procedures with significant ocular morbidity. WhenTrabeculectomy, VC, and NPT are thought to have a low chance forsuccess, a number of implantable drainage devices have been used toensure that the desired filtration and outflow of aqueous humor throughthe surgical opening will continue. The risk of placing a glaucomadrainage implant also includes hemorrhage, infection and postoperativedouble vision that is a complication unique to drainage implants.

[0021] Examples of implantable shunts or devices for maintaining anopening for the release of aqueous humor from the anterior chamber ofthe eye to the sclera or space underneath conjunctiva have beendisclosed in U.S. Pat. Nos. 6,007,511 (Prywes), 6,007,510 (Nigam),5,893,837 (Eagles et al.), 5,882,327 (Jacob), 5,879,319 (Pynson et al.),5,807,302 (Wandel), 5,752,928 (de Roulhac et al.), 5,743,868 (Brown etal.), 5,704,907 (Nordquist et al.), 5,626,559 (Solomon), 5,626,558(Suson), 5,601,094 (Reiss), RE. 35,390 (Smith), 5,558,630 (Fisher),5,558,629 (Baerveldt et al.), 5,520,631 (Nordquist et al.), 5,476,445(Baerveldt et al.), 5,454,796 (Krupin), 5,433,701 (Rubinstein),5,397,300 (Baerveldt et al.), 5,372,577 (Ungerleider), 5,370,607(Memmen), 5,338,291 (Speckman et al.), 5,300,020 (L'Esperance, Jr.),5,178,604 (Baerveldt et al.), 5,171,213 (Price, Jr.), 5,041,081(Odrich), 4,968,296 (Ritch et al.), 4,936,825 (Ungerleider), 4,886,488(White), 4,750,901 (Molteno), 4,634,418 (Binder), 4,604,087 (Joseph),4,554,918 (White), 4,521,210 (Wong), 4,428,746 (Mendez), 4,402,681 (Haaset al.), 4,175,563 (Arenberg et al.) and 4,037,604 (Newkirk).

[0022] All of the above techniques and variations thereof have numerousdisadvantages and moderate success rates. They involve substantialtrauma to the eye and require great surgical skill by creating a holeover the full thickness of the sclera/comea into the subconjunctivalspace. Furthermore, normal physiological outflow pathways are not used.The procedures are mostly performed in an operating room generating afacility fee, anesthesiologist's professional fee and have a prolongedrecovery time for vision. The complications of filtration surgery haveinspired ophthalmic surgeons to look at other approaches to loweringintraocular pressure.

SUMMARY OF THE INVENTION

[0023] The trabecular meshwork and juxtacanilicular tissue togetherprovide the majority of resistance to the outflow of aqueous and, assuch, are logical targets for surgical removal in the treatment ofopen-angle glaucoma. In addition, minimal amounts of tissue are alteredand existing physiologic outflow pathways are utilized. Trabecularbypass surgery has the potential for much lower risks of choroidalhemorrhage, infection and uses existing physiologic outflow mechanisms.This surgery could be performed under topical anesthesia in aphysician's office with rapid visual recovery.

[0024] International PCT Publication No. WO 01/78631, published Oct. 25,2001 (Appl. No. PCT/US01/07398, filed Mar. 8, 2001), by someco-inventor(s) of this patent application, entitled “APPARATUS ANDMETHOD FOR TREATING GLAUCOMA”, the entire contents of which are herebyincorporated by reference herein, discloses a seton implant positionedthrough the trabecular meshwork so that an inlet end of the setonimplant is exposed to the anterior chamber of the eye and an outlet endis positioned into Schlemm's canal at about an exterior surface of thetrabecular meshwork for permitting aqueous humor to flow out of theanterior chamber. An ab interno microsurgery for creating an opening inthe trabecular meshwork.

[0025] International PCT Publication No. 01/97727, published Dec. 27,2001 (Appl. No. PCT/US01/18541, filed Jun. 6, 2001), by someco-inventor(s) of this patent application, entitled “STENTED TRABECULARSHUNT AND METHODS THEREOF”, the entire contents of which are herebyincorporated by reference herein, discloses a stented trabecular shuntcomprising an outlet section that is expandable and adapted forstabilizing within Schlemm's canal with an ab interno microsurgery forcreating an opening in the trabecular meshwork.

[0026] International PCT Publication No. 02/36052, published May 10,2002 (Appl. No. PCT/US01/14783, filed May 8, 2001), by someco-inventor(s) of this patent application, entitled “GLAUCOMA TREATMENTDEVICE”, the entire contents of which are hereby incorporated byreference herein, discloses a device for directing the flow of aqueoushumor through the lumen to Schlemm's canal with an ab internomicrosurgery for creating an opening in the trabecular meshwork.

[0027] The ab interno microsurgery disclosed in the above WIPO PCTpublications/applications has a common disadvantage of first using apiercing instrument for creating an opening in the trabecular meshwork.The piercing instrument goes into the anterior chamber, creates anopening in the trabecular meshwork and is then withdraw from theanterior chamber before a trabecular stent is implanted in a separateinsertion. Therefore, there is a great clinical need for the treatmentof glaucoma by a trabecular bypass surgery using a micro stent to bypassdeficient trabecular meshwork in a one-step simple procedure. One objectof the invention is to provide a trabecular stent and methods fortreating elevated intraocular pressure with an ab interno microsurgeryfor creating an opening in the trabecular meshwork by a piercing memberof the applicator slidably through the lumen of the stent in a combinedpiercing and stent implanting one-step inserting procedure.

[0028] In some preferred embodiments, the stent has an inlet portionconfigured to extend through a portion of the trabecular meshwork of aneye, and an outlet portion configured to extend into Schlemm's canal ofthe eye, wherein the outlet portion may have a lumen with an ovalcross-section having a long axis.

[0029] The outlet portion in certain embodiments has a longitudinalaxis, such that the long axis of the oval cross-section and thelongitudinal axis of the outlet portion define a plane, the inletportion having a longitudinal axis which lies outside the plane at anangle thereto.

[0030] In some preferred arrangements, the stent comprises an inletportion configured to extend through a portion of the trabecularmeshwork, an outlet portion configured to extend into Schlemm's canal,and at least one protrusion on the outlet portion configured to exerttraction against an inner surface of Schlemm's canal. This protrusioncan comprise at least one barb or ridge.

[0031] Some preferred embodiments comprise an inlet portion configuredto extend through a portion of the trabecular meshwork, an outletportion configured to extend into Schlemm's canal, and a one-way leaflettype valve within the inlet and/or outlet portions.

[0032] Some aspects relate to a method for delivering a stent within aneye. The method generally comprising providing an elongate applicatorhaving a piercing member intended to pass through the lumen of thestent, advancing a distal end of the applicator with the piercing memberthrough at least a portion of the trabecular meshwork of the eye,retrieving the piercing member, advancing the stent along the applicatortoward the distal end, and positioning the stent to conduct aqueoushumor between the anterior chamber of the eye and Schlemm's canal.

[0033] In certain embodiments, the advancing of the applicator comprisesadvancing it from the anterior chamber into the trabecular meshwork. Infurther embodiments, the positioning comprises positioning an end of thestent within Schlemm's canal adjacent to an aqueous collection channel.

[0034] Certain preferred embodiments include an apparatus for deliveringa stent to the anterior chamber of an eye comprising an elongateapplicator having a lumen, an outer surface, and a distal end; aremovable, elongate piercing member within the lumen of the applicator;a slidable stent delivery mechanism configured to permit the stent to beadvanced and to be positioned in about the trabecular meshwork of theeye. The piercing member is positioned at the distal end of theapplicator, wherein the piercing member is slidably advanceable throughthe lumen of the stent. The piercing member can be selected from thegroup consisting of a knife, a laser probe, a pointed guide member, andan energy source, such as radiofrequency (RF), ultrasonic energy, fiberoptic laser, microwave, focused ultrasound and the like. The apparatuscan also further comprise an opening in the outer surface of theapplicator configured to allow fluid infusion into the eye.

[0035] In further preferred embodiments, an apparatus for delivering astent in an eye comprises an elongate applicator member adapted forinsertion into an anterior chamber of the eye, the elongate memberhaving a distal end portion configured to retain the stent therein, thedistal end portion comprising a piercing member configured to form anopening in the trabecular meshwork of the eye for receipt of the stent,such that one end of the stent is in Schlemm's canal. The elongateapplicator member can further comprise a lumen which conducts fluidtoward the distal end portion.

[0036] Some preferred embodiments provide further surgical treatment ofglaucoma (trabecular bypass surgery) at the level of trabecular meshworkand restore existing physiological outflow pathways. An implant bypassesdiseased trabecular meshwork at the level of trabecular meshwork andwhich restores existing physiological outflow pathways. The implant hasan inlet end, an outlet end and a lumen therebetween. The inlet end ispositioned in the anterior chamber at the level of the internaltrabecular meshwork and the outlet end is positioned at about theexterior surface of the diseased trabecular meshwork and/or into fluidcollection channels of the existing outflow pathways.

[0037] In accordance with some preferred methods, trabecular bypasssurgery creates an opening or a hole through the diseased trabecularmeshwork through minor microsurgery. To prevent “filling in” of thehole, a biocompatible elongated implant is placed within the hole as astent, which may include, for example, a hollow tube. In one exemplaryembodiment, the stent implant may be positioned across the diseasedtrabecular meshwork alone and it does not extend into the eye wall orsclera. In another embodiment, the inlet end of the implant is exposedto the anterior chamber of the eye while the outlet end is positioned atthe exterior surface of the trabecular meshwork. In another exemplaryembodiment, the outlet end is positioned at and over the exteriorsurface of the trabecular meshwork and into the fluid collectionchannels of the existing outflow pathways. In still another embodiment,the outlet end is positioned in the Schlemm's canal. In a modifiedembodiment, the outlet end enters into fluid collection channels up tothe level of the aqueous veins or episcleral aqueous veins.

[0038] According to some preferred embodiments, the stent implant ismade of biocompatible material, which is either hollow or porous toallow the flow of aqueous humor or solid biocompatible material thatimbibes aqueous. The material for the stent may be selected from thegroup consisting of porous material, semi-rigid material, soft material,hydrophilic material, hydrophobic material, hydrogel, elastic material,and the like.

[0039] The trabecular stent, particularly the porous stent, may havehigh water affinity that is hydrophilic and tissue compatible. One ormore drugs may be loaded onto the trabecular stent and slowly releasedto the surrounding tissue effective to treat glaucoma and/or otherophthalmology abnormalities.

[0040] In accordance with further preferred embodiments, the stentimplant may be rigid or it may be made of relatively soft material andis somewhat curved at its distal section to fit into the existingphysiological outflow pathways, such as Schlemm's canal. The distalsection inside the outflow pathways may have an oval shape to stabilizethe stent in place without undue suturing. Stabilization or retention ofthe stent may be further strengthened by a tapered end and/or by atleast one ridge or rib on the exterior surface of the distal section ofthe stent, or other surface alterations designed to retain the stent.

[0041] In some embodiments, the stent may include a micropump, one-wayvalve, or semi-permeable membrane if reflux of red blood cells or serumprotein becomes a clinical problem. It may also be useful to use abiocompatible material that hydrates and expands after implantation sothat the stent is locked into position around the trabecular meshworkopening or around the distal section of the stent.

[0042] One of the advantages of trabecular bypass surgery, as disclosedherein, and the use of a stent implant to bypass diseased trabecularmeshwork at the level of trabecular meshwork and thereby use existingoutflow pathways is that the treatment of glaucoma is substantiallysimpler than in existing therapies. A further advantage of somepreferred embodiments is the utilization of simple microsurgery that maybe performed on an outpatient basis with rapid visual recovery andgreatly decreased morbidity. Finally, a distinctly different approach isused than is found in existing implants. Physiological outflowmechanisms are used or re-established by the implant of some preferredembodiments, in contra-distinction with previously disclosedmethodologies.

[0043] Some aspects of the invention provide a trabecular stent to beinserted through an opening of the deficient trabecular meshwork,wherein the opening is created by using a cutting instrument slid insidea lumen of the trabecular stent in a combined one-step cutting andimplanting inserting operation.

[0044] Some other aspects of the invention provide a method for cleaningthe obstructed lumen of a trabecular stent by an applicator that has apiercing member that is slidably advanceable approaching or through theobstructed lumen of the stent.

[0045] For purposes of summarizing the invention, certain aspects,advantages and novel features of the invention have been describedherein above. Of course, it is to be understood that not necessarily allsuch advantages may be achieved in accordance with any particularembodiment of the invention. Thus, the invention may be embodied orcarried out in a manner that achieves or optimizes one advantage orgroup of advantages as taught or suggested herein without necessarilyachieving other advantages as may be taught or suggested herein.

[0046] All of these embodiments are intended to be within the scope ofthe invention herein disclosed. These and other embodiments of theinvention will become readily apparent to those skilled in the art fromthe following detailed description of the preferred embodiments havingreference to the attached figures, the invention not being limited toany particular preferred embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Having thus summarized the general nature of the invention andsome of its features and advantages, certain preferred embodiments andmodifications thereof will become apparent to those skilled in the artfrom the detailed description herein having reference to the figuresthat follow, of which:

[0048]FIG. 1 is a sectional view of an eye for illustration purposes.

[0049]FIG. 2 is a close-up sectional view showing the anatomical diagramof trabecular meshwork and the anterior chamber of the eye of FIG. 1.

[0050]FIG. 3 is front elevation view of a stent implant having featuresand advantages in accordance with one embodiment of the invention.

[0051]FIG. 4 is a top plan view of the stent implant of FIG. 3 alongline 4-4 of FIG 3.

[0052]FIG. 5 is a bottom end view of the stent implant of FIG. 3 alongline 5-5 of FIG 3.

[0053]FIG. 6 is a simplified schematic illustration of the stent implantof FIG. 3 implanted within the eye having features and advantages inaccordance with one embodiment of the invention.

[0054]FIG. 7A is a partially cross-section view of an apparatusillustrating a first step of delivering the stent implant of FIG. 3 byholding the stent implant inside a lumen of an applicator and havingfeatures and advantages in accordance with one embodiment of theinvention.

[0055]FIG. 7B is a partially cross-section view of the apparatus of FIG.7A illustrating a second step of delivering the stent implant of FIG. 3by creating an opening in the trabecular meshwork with a piercing memberand having features and advantages in accordance with one embodiment ofthe invention..

[0056]FIG. 7C is a partially cross-section view of the apparatus of FIG.7A illustrating a third step of delivering the stent implant of FIG. 3by retracting the piercing member inside the lumen of the applicator andhaving features and advantages in accordance with one embodiment of theinvention.

[0057]FIG. 7D is a is a partially cross-section view of the apparatus ofFIG. 7A illustrating a fourth step of delivering the stent implant ofFIG. 3 by inserting the stent implant through the trabecular meshworkand having features and advantages in accordance with one embodiment ofthe invention.

[0058]FIG. 8 is a cross-section view of the apparatus of FIGS. 7A-7Dalong line 8-8 of FIG. 7A.

[0059]FIG. 9 illustrates one preferred exemplary method for placing thestent implant of FIG. 3 at the implant site having features andadvantages in accordance with one embodiment of the invention.

[0060]FIG. 10 is a partially cross-section view of an apparatus forclearing an obstructed lumen of the implanted trabecular stent of FIG. 3having features and advantages in accordance with one embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] The drawings generally illustrate a method for the treatment ofglaucoma by trabecular bypass surgery. In particular, a stent implant isused to bypass diseased or deficient trabecular meshwork at the level oftrabecular meshwork to use or restore existing outflow pathways andmethods thereof are disclosed.

[0062] While the description sets forth various embodiment specificdetails, it will be appreciated that the description is illustrativeonly and should not be construed in any way as limiting the invention.Furthermore, various applications of the invention, and modificationsthereto, which may occur to those who are skilled in the art, are alsoencompassed by the general concepts described herein and below.

[0063] For background illustration purposes, FIG. 1 shows a sectionalview of an eye 10, while FIG. 2 shows a close-up view, showing therelative anatomical locations of a trabecular meshwork 21, an anteriorchamber 20, and Schlemm's canal 22. Thick collagenous tissue known assclera 11 covers the entire eye 10 except that portion covered by thecornea 12. The cornea 12 is a thin transparent tissue that focuses andtransmits light into the eye and through a pupil 14 which is a circularhole in the center of an iris 13 (colored portion of the eye). Thecornea 12 merges into the sclera 11 at a juncture referred to as alimbus 15. A ciliary body 16 begins internally in the eye and extendsalong the interior of the sclera 11 and is coextensive with a choroid17. The choroid 17 is a vascular layer of the eye, located between thesclera 11 and an underlying retina 18. An optic nerve 19 transmitsvisual information to the brain and is the anatomic structure that isprogressively destroyed by glaucoma.

[0064] The anterior chamber 20 of the eye 10 (FIGS. 1 and 2), which isbound anteriorly by the cornea 12 and posteriorly by the iris 13 and alens 26, is filled with aqueous humor (also herein referred to as“aqueous”). Aqueous is produced primarily by the ciliary body 16 andreaches an anterior chamber angle 25, formed between the iris 13 and thecornea 12, through the pupil 14.

[0065] Referring in particular to FIGS. 1 and 2, in a normal eye,aqueous is removed from the anterior chamber 20 through the trabecularmeshwork 21. Aqueous passes through trabecular meshwork 21 intoSchlemm's canal 22 and thereafter through a plurality of aqueous veins23, which merge with blood-carrying veins, and into systemic venouscirculation. Intraocular pressure (IOP) of the eye 10 is maintained byan intricate balance between secretion and outflow of aqueous in themanner described above. Glaucoma is, in most cases, characterized by anexcessive buildup of aqueous fluid in the anterior chamber 20 whichleads to an increase in intraocular pressure. Fluids are relativelyincompressible, and thus intraocular pressure is distributed relativelyuniformly throughout the eye 10.

[0066] As shown in FIG. 2, the trabecular meshwork 21 is adjacent asmall portion of the sclera 11. Exterior to the sclera 11 is aconjunctiva 24. Traditional procedures that create a hole or opening forimplanting a device through the tissues of the conjunctiva 24 and sclera11 involve extensive surgery, as compared to surgery for implanting adevice through the trabecular meshwork 21, as described herein, whichultimately resides entirely within the confines of the sclera 11 andcornea 12.

[0067] Surgical methods and related medical devices for treatingglaucoma are disclosed. The method comprises trabecular bypass surgery,which involves bypassing diseased trabecular meshwork with the use of astent implant. The stent implant is inserted into an opening created inthe trabecular meshwork by a piercing member that is slidablyadvanceable through the lumen of the stent implant for supporting theimplant insertion. The stent implant is positioned through thetrabecular meshwork so that an inlet end of the stent implant is exposedto the anterior chamber of the eye and an outlet end is positioned intofluid collection channels at about an exterior surface of the trabecularmeshwork or up to the level of aqueous veins.

[0068] Some embodiments relate to a method of increasing aqueous humoroutflow in an eye of a patient to reduce the intraocular pressure (IOP)therein. In one embodiment, the method comprises bypassing diseased ordeficient trabecular meshwork at the level of the trabecular meshworkand thereby restoring existing outflow pathways. In another embodiment,the method comprises bypassing diseased trabecular meshwork at a levelof the trabecular meshwork with a stent implant and using existingoutflow pathways.

[0069] Stent Implant

[0070] FIGS. 3-5 show different views of a stent implant 31 constructedin accordance with one embodiment. FIG. 6 illustrates the implantationof the stent 31 within the eye 10. The stent implant 31 may comprise anelongated stent or other appropriate shape, size or configuration. Inthe illustrated embodiment, the stent implant 31 is in the form anelongated tubular element and generally comprises an inlet or proximalsection 30 an outlet or distal section 33, a medial section 32therebetween and a lumen or passage 34 extending therethrough.

[0071] Referring in particular to FIGS. 3-6, and as best seen in FIG. 6,in use, the inlet section 30 is positioned in the anterior chamber 20 ofthe eye 10 at about an interior surface 46 of the trabecular meshwork 21and the outlet end or the outlet section 33 is positioned at about anexterior surface 47 of the diseased trabecular meshwork 21. Asillustrated in FIG. 6, the trabecular meshwork interior side or surface46 faces the anterior chamber 20 and the trabecular meshwork exteriorside or surface 47 faces Schlemm's canal 22.

[0072] In some embodiments, the outlet section 33 may be positioned intofluid collection channels of the existing outflow pathways. In someembodiments, the existing outflow pathways comprise Schlemm's canal 22.The outlet section 33 may be further positioned into fluid collectionchannels up to the level of the aqueous veins 23 (see FIG. 2) with thestent 31 inserted within the eye 10. In general, the stent implant maybe an axisymmetric stent or other configuration suitable for use withthe methods taught or suggested herein.

[0073] In the illustrated embodiment of FIGS. 3-6, the proximal inletsection or portion 30 is generally in the form of a circular disc andhas a proximal-most end or upper surface 41 and a lower surface 42. Inmodified embodiments, the stent proximal section may be shaped in othersuitable manners with efficacy, as needed or desired, for example, oval,ellipsoidal, and the like. As best seen in FIG. 6, when the stent 31 isimplanted within the eye 10, the upper surface 41 is exposed to orwithin the anterior chamber 20 while the lower surface 42 is seated onor abuts against the interior surface 46 of the trabecular meshwork 21to stabilize the implanted stent 31.

[0074] In the illustrated embodiment of FIGS. 3-6, the medial or middlesection or portion 32 is generally cylindrical in shape and has agenerally circular cross-section. In modified embodiments, the stentmedial section may be shaped in other suitable manners with efficacy, asneeded or desired, for example, oval, ellipsoidal, and the like. As bestseen in FIG. 6, when the stent 31 is implanted within the eye 10, themedial section 32 is received within an opening 103 within thetrabecular meshwork 21. Preferably, the middle section 32 is configuredand sized to fit the opened region 103 of the trabecular meshwork 21.

[0075] In the illustrated embodiment of FIGS. 3-6, the distal outletsection or portion 33 has an upper surface 39, a distal-most end orsurface 44 and a tapered or curved outer surface 45 therebetween. Theouter periphery of the outlet section 33 is generally circumferential orcircular in shape. In modified embodiments, the stent distal section maybe shaped in other suitable manners with efficacy, as needed or desired,for example, oval, ellipsoidal, and the like.

[0076] As best seen in FIG. 6, when the stent 31 is implanted within theeye 10, the distal section 33 is received within Schlemm's canal 22 andthe upper surface 39 abuts against the exterior surface 47 of thetrabecular meshwork 21 to stabilize the implanted stent 31. The distalsection 33 may have a bulged outlet end or protrusion 38 and/or otherbulging or protruding retention device or mechanism for stabilizing thestent implant 31 inside the existing outflow pathways afterimplantation, for example, a barb, among others.

[0077] For stabilization purposes, the outer surface of the distalsection 33 may comprise a stubbed surface, a ribbed surface, a surfacewith pillars, a textured surface, and the like, or a combinationthereof. In some embodiments, the distal section 33 may be curved orbent at an angle with reference to the proximal section 30 and/or themedial section 32. For example, the stent implant my be substantiallyL-shaped or T-shaped with the proximal and/or medial sections comprisinga snorkel portion extending through the trabecular meshwork 21 and thedistal section extending within Schlemm's canal 22 and/or other aqueousoutflow pathways. The angulations(s) may be substantially perpendicular,acute angled or obtuse angled, as needed or desired.

[0078] In the illustrated embodiment of FIGS. 3-6, the lumen 34 has anupper opening, orifice or port 35 at the proximal end 41 and a loweropening, orifice or port 35 at the distal end 44. The lumen 34 has agenerally circumferential or circular cross-section with a tapered orcurved surface 48 within the distal section 33. In modified embodiments,the stent lumen may be shaped in other suitable manners with efficacy,as needed or desired, for example, oval, ellipsoidal, and the like, orsome other shape configured and adapted for effective aqueous entranceand transmission. In some embodiments, the stent implant 31 may have aplurality of lumens to facilitate multiple flow transportation, asneeded or desired.

[0079] As best seen in FIG. 4, the lumen upper orifice 35 is generallycircular or round in shape. In modified embodiments, the lumen upperorifice may be shaped in other suitable manners with efficacy, as neededor desired, for example, oval, ellipsoidal, and the like, or some othershape configured and adapted for effective aqueous entrance andtransmission. The stent implant 31 may comprise one or more inletopenings 35 at the inlet section 30 to allow adequate outflow ofaqueous, as needed or desired.

[0080] As best seen in FIG. 5, the lumen lower orifice 36 is generallycircular or round in shape. In modified embodiments, the lumen lowerorifice may be shaped in other suitable manners with efficacy, as neededor desired, for example, oval, ellipsoidal, and the like, or some othershape configured and adapted for effective aqueous transmission enablingto conform to the shape and size of the existing outflow pathways. Thisconfiguration and/or that of the distal section 44 may match the contourof Schlemm's canal 22 to stabilize the stent 31 with respect to the irisand cornea by preventing unexpected movement. The stent implant 31 maycomprise one or more outlet ports 36 at the outlet section 33 to allowadequate outflow of aqueous, as needed or desired.

[0081] As best seen in FIG. 6, aqueous from the anterior chamber 20enters the lumen 34 through orifice 35 and passes through the stent in adirection generally indicated by arrow 40 and exits through the lumenorifice 36 into Schlemm's canal 22 in a direction generally indicated byarrows 49. Advantageously, the stent implant 31 assists in facilitatingthe outflow of aqueous in an outward direction 40 through the stent 31and into Schlemm's canal 22 and subsequently into the aqueous collectorsand the aqueous veins 23 (see FIG. 2) so that the intraocular pressure(IOP) is balanced.

[0082] Preferably, the entire exposed surface of the stent 31 (FIGS.3-6) is biocompatible and tissue compatible so that theinteraction/irritation between its surface and the surrounding tissue oraqueous is minimized. In modified embodiments, selected portions orsurfaces of the stent 31 may comprise a biocompatible and/or tissuecompatible material, as needed or desired.

[0083] As the skilled artisan will readily appreciate, the stent implant31 of the illustrated embodiment may be dimensioned in a wide variety ofmanners. In an exemplary embodiment, the stent implant 31 has a lengthbetween about 0.3 millimeters (mm) to about over 1 centimeter (cm),depending on the body cavity where the stent implant is to be implanted.The outside or outer diameter of the stent implant 31 may range fromabout 30 micrometers or microns (μm) to about 500 μm or more. The lumendiameter is preferably in the range between about 10 μm to about 150 μmor larger. In other embodiments, the stent implant 31 may be dimensionedin modified manners with efficacy, as required or desired, giving dueconsideration to the goals of achieving one or more of the benefits andadvantages as taught or suggested herein.

[0084] In some embodiments, and as discussed further herein, a method isdisclosed for increasing aqueous humor outflow in an eye of a patient toreduce an intraocular pressure therein. The method comprises (a)creating an opening in trabecular meshwork by a piercing member of anapplicator, wherein the trabecular meshwork comprises an interior sideand exterior side, the piercing member is slidably moveable through thelumen of the stent; (b) inserting a stent implant into the opening inthe trabecular meshwork; and (c) transporting the aqueous humor by thestent implant to bypass the trabecular meshwork at the level of thetrabecular meshwork from the interior side facing the anterior chamberto the exterior side facing Schlemm's canal of the trabecular meshwork.

[0085] In one embodiment, the stent implant 31 (FIGS. 3-6) comprises abiocompatible material, such as a medical grade silicone, for example,the material sold under the trademark Silastic™, which is available fromDow Corning Corporation of Midland, Mich., or polyurethane, which issold under the trademark Pellethane™, which is also available from DowCorning Corporation. In another embodiment, other biocompatiblematerials (biomaterials) may be used, such as polyvinyl alcohol,polyvinyl pyrolidone, collagen, heparinized collagen,tetrafluoroethylene, fluorinated polymer, fluorinated elastomer,flexible fused silica, polyolefin, polyester, polysilicon, stainlesssteel, Nitinol, titanium, a mixture of biocompatible materials,combinations thereof, and the like. In yet another embodiment, acomposite biocompatible material may be utilized by surface coating theabove-mentioned biomaterial, wherein the coating material may beselected from the group consisting of polytetrafluoroethylene (PTFE),polyimide, hydrogel, heparin, therapeutic drugs, and the like.

[0086] In one embodiment, the material for the stent 31 (FIGS. 3-6)comprises one or more of a porous material, a semi-rigid material, asoft material, a hydrophilic material, a hydrophobic material, ahydrogel, an elastic material, or combinations thereof, and the like.The trabecular stent 31, particularly the porous stent, may have highwater affinity that is hydrophilic and tissue compatible. One or moresuitable drug may be coated or loaded onto the trabecular stent 31 andslowly released to the surrounding tissue which are effective to treatglaucoma and/or other ophthalmology abnormalities. As is well known inthe art, a device coated or loaded with a slow-release drug can haveprolonged effects on local tissue surrounding the device. Theslow-release delivery can be designed such that an effective amount ofdrug is released over a desired duration.

[0087] In one embodiment, the stent device 31 (FIGS. 3-6) comprises abiodegradable (also including bioerodible) material admixed with a drugfor drug slow-release into ocular tissues. In another embodiment,polymer films may function as drug containing release devices wherebythe polymer films are coupled or secured to the device 31. The polymerfilms may be designed to permit the controlled release of the drug at achosen rate and for a selected duration, which may also be episodic orperiodic. Such polymer films may be synthesized such that the drug isbound to the surface or resides within a pore in the film so that thedrug is relatively protected from enzymatic attack. The polymer filmsmay also be modified to alter their hydrophilicity, hydrophobicity andvulnerability to platelet adhesion and enzymatic attack.

[0088] In some embodiments, the implant device 31 (FIGS. 3-6) is usedfor a direct release of pharmaceutical preparations into ocular tissues.As discussed above, pharmaceuticals may be compounded within the device31 or form a coating on the device 31. Any known drug therapy forglaucoma and/or ophthalmology diseases may be utilized, including butnot limited to, the following:

[0089] U.S. Pat. No. 6,403,590, issued Jun. 11, 2002, the entirecontents of which are hereby incorporated by reference herein, disclosesisoquinolinesulfonyl compounds used in ophthalmic compositions to treatglaucoma or other ischemic-borne ocular disorders such as retinopathiesor optic neuropathies. These compounds vasodilate ocular blood vessels,lower IOP and prevent or reduce the progression of visual field loss;

[0090] U.S. Pat. No. 6,274,138, issued Aug. 14, 2001 and U.S. Pat. No.6,231,853, issued May 15, 2001, the entire contents of each one of whichare hereby incorporated by reference herein, disclose the function ofmitochondria and toxic drugs synthesized as a metabolic byproduct withinmitochondria of cells. Perry and associates (Perry HD et al. “Topicalcyclosporin A in the management of postkeratoplasty glaucoma” Cornea16:284-288, 1997) report that topical cyclosporin-A has been shown toreduce post-surgical increases in intraocular pressure. It is proposedthat such compounds with known effects on mitochondrial stability mightbe effective in treating trabecular meshwork. An antagonistic drug toneutralize the toxic byproduct or a stabilizing drug to effectmitochondrial stability is believed able to restore the mitochondriafunction and subsequently mitigate the dysfunction of the trabecularmeshwork;

[0091] U.S. Pat. No. 6,201,001, issued Mar. 13, 2001, the entirecontents of which are hereby incorporated by reference herein, disclosesImidazole antiproliferative agents useful for neovascular glaucoma;

[0092] U.S. Pat. No. 6,228,873, issued May 8, 2001, the entire contentsof which are hereby incorporated by reference herein, discloses a newclass of compounds that inhibit function of sodium chloride transport inthe thick ascending limb of the loop of Henle, wherein the preferredcompounds useful are furosemide, piretanide, benzmetanide, bumetanide,torasernide and derivatives thereof;

[0093] U.S. Pat. No. 6,194,415, issued Feb. 27, 2001, the entirecontents of which are hereby incorporated by reference herein, disclosesa method of using quinoxoalines (2-imidazolin-2-ylamino) in treatingneural injuries (e.g. glaucomatous nerve damage);

[0094] U.S. Pat. No. 6,060,463, issued May 9, 2000 and U.S. Pat. No.5,869,468, issued Feb. 9, 1999, the entire contents of each one of whichare hereby incorporated by reference herein, disclose treatment ofconditions of abnormally increased intraocular pressure byadministration of phosphonylmethoxyalkyl nucleotide analogs and relatednucleotide analogs;

[0095] U.S. Pat. No. 5,925,342, issued Jul. 20, 1999, the entirecontents of which are hereby incorporated by reference herein, disclosesa method for reducing intraocular pressure by administration ofpotassium channel blockers;

[0096] U.S. Pat. No. 5,814,620, issued Sep. 29, 1998, the entirecontents of which are hereby incorporated by reference herein, disclosesa method of reducing neovascularization and of treating variousdisorders associated with neovascularization. These methods includeadministering to a tissue or subject a synthetic oligonucleotide;

[0097] U.S. Pat. No. 5,767,079, issued Jun. 16, 1998, the entirecontents of which are hereby incorporated by reference herein, disclosesa method for treatment of ophthalmic disorders by applying an effectiveamount of Transforming Growth Factor-Beta (TGF-beta) to the affectedregion;

[0098] U.S. Pat. No. 5,663,205, issued Sep. 2, 1997, the entire contentsof which are hereby incorporated by reference herein, discloses apharmaceutical composition for use in glaucoma treatment which containsan active ingredient5-[1-hydroxy-2-[2-(2-methoxyphenoxyl)ethylamino]ethyl]-2-methylbenzenesulfonamide.This agent is free from side effects, and stable and has an excellentintraocular pressure reducing activity at its low concentrations, thusbeing useful as a pharmaceutical composition for use in glaucomatreatment;

[0099] U.S. Pat. No. 5,652,236, issued Jul. 29, 1997, the entirecontents of which are hereby incorporated by reference herein, disclosespharmaceutical compositions and a method for treating glaucoma and/orocular hypertension in the mammalian eye by administering thereto apharmaceutical composition which contains as the active ingredient oneor more compounds having guanylate cyclase inhibition activity. Examplesof guanylate cyclase inhibitors utilized in the pharmaceuticalcomposition and method of treatment are methylene blue, butylatedhydroxyanisole and N-methylhydroxylamine;

[0100] U.S. Pat. No. 5,547,993, issued Aug. 20, 1996, the entirecontents of which are hereby incorporated by reference herein, disclosesthat 2-(4methylaminobutoxy) diphenylmethane or a hydrate orpharmaceutically acceptable salt thereof have been found useful fortreating glaucoma;

[0101] U.S. Pat. No. 5,502,052, issued Mar. 26, 1996, the entirecontents of which are hereby incorporated by reference herein, disclosesuse of a combination of apraclonidine and timolol to control intraocularpressure. The compositions contain a combination of an alpha-2 agonist(e.g., para-amino clonidine) and a beta blocker (e.g., betaxolol);

[0102] U.S. Pat. No. 6,184,250, issued Feb. 6, 2001, the entire contentsof which are hereby incorporated by reference herein, discloses use ofcloprostenol and fluprostenol analogues to treat glaucoma and ocularhypertension. The method comprises topically administering to anaffected eye a composition comprising a therapeutically effective amountof a combination of a first compound selected from the group consistingof beta-blockers, carbonic anhydrase inhibitors, adrenergic agonists,and cholinergic agonists; together with a second compound;

[0103] U.S. Pat. No. 6,159,458, issued Dec. 12, 2000, the entirecontents of which are hereby incorporated by reference herein, disclosesan ophthalmic composition that provides sustained release of a watersoluble medicament formed by comprising a crosslinked carboxy-containingpolymer, a medicament, a sugar and water;

[0104] U.S. Pat. No. 6,110,912, issued Aug. 29, 2000, the entirecontents of which are hereby incorporated by reference herein, disclosesmethods for the treatment of glaucoma by administering an ophthalmicpreparation comprising an effective amount of a non-corneotoxicserine-threonine kinase inhibitor, thereby enhancing aqueous outflow inthe eye and treatment of the glaucoma. In some embodiments, the methodof administration is topical, whereas it is intracameral in otherembodiments. In still further embodiments, the method of administrationis intracanalicular;

[0105] U.S. Pat. No. 6,177,427, issued Jan. 23, 2001, the entirecontents of which are hereby incorporated by reference herein, disclosescompositions of non-steroidal glucocorticoid antagonists for treatingglaucoma or ocular hypertension; and

[0106] U.S. Pat. No. 5,952,378, issued Sep. 14, 1999, the entirecontents of which are hereby incorporated by reference herein, disclosesthe use of prostaglandins for enhancing the delivery of drugs throughthe uveoscleral route to the optic nerve head for treatment of glaucomaor other diseases of the optic nerve as well as surrounding tissue. Themethod for enhancing the delivery to the optic nerve head comprisescontacting a therapeutically effective amount of a compositioncontaining one or more prostaglandins and one or more drug drugs withthe eye at certain intervals.

[0107] Surgical Methods and Apparatus

[0108] FIGS. 7A-7D show one embodiment of an apparatus and illustratesteps of using it to create an opening in the trabecular meshwork anddelivering a stent implant to a surgical site within the eye. FIG. 8 isanother view of the apparatus highlighting certain features of theapparatus.

[0109] Referring to the illustrated embodiment of FIGS. 7A-8, theapparatus or stent-delivery applicator 56 generally comprises agenerally cylindrical outer housing, cover or sheath 50, a lumen orpassage 60, a piercing member, device or mechanism 62 and astent-delivery device or mechanism 64. The applicator or applicatorportion 56 has an opening or orifice 81 at a distal-most end 71. Thestent implant 31 or other suitable stent device is loaded within theapplicator 56 at about the distal end or section 71 and resides withinthe applicator lumen 60.

[0110] In the illustrated embodiment of FIGS. 7A-8, the piercing member62 generally comprises a distal section 82 having a distal end orpiercing tip 61, a medial body portion or section 67 and a proximaldeployment section or mechanism 63. As illustrated by the drawings, thepiercing member 62 is moveably located or mounted within the lumen 60 ofthe applicator 56. The piercing member distal section 82, distal end 61along with the body 67 can be moved forwardly (in the general directionof arrow 83) and backwardly (in the general direction of arrow 84) bythe deployment mechanism 63 inside the lumen 60 of the applicator 56.

[0111] The piercing member distal end 61 (FIGS. 7A-7D) is sized andconfigured to effectively create an opening in the trabecular meshwork21 enabling the stent 31 to be inserted with little resistance or effortand implanted (as shown, for example, in FIG. 6). In accordance with oneaspect, the means or device for forming a hole, opening or incision inthe trabecular mesh 21 may comprise a microknife, a pointed guidewire, asharpened trephine, a screw shaped trephine, an irrigating tubing, aretinal pick, a microcurrette, or the like. In accordance with anotheraspect, the trabecular meshwork 21 may be pierced with anenergy-assisted device, such as a laser optic fiber, a radiofrequency(RF) electrode, an ultrasonic transducer, a microwave antenna, a heatedor cooled instrument or the like. Fiberoptic lasers that are suitablefor such use include, for example, Q-switched Neodymiun (Nd):YAG lasers,Erbium:YAG lasers, cold C0 ₂ lasers and the like.

[0112] As best seen in FIG. 8, the piercing member body 67 includes aplurality of holes or openings 43. In the illustrated embodiment, thebody portion 67 includes three holes 43 though fewer or more holes maybe efficaciously utilized, as needed or desired. The holes 43 are sizedand configured to provide passages for stent-delivery mechanism 64 toengage and disengage from the stent 31 during implantation of the stent31.

[0113] In the illustrated embodiment of FIGS. 7A-8, the deploymentmechanism 63 provides for the movement of the piercing member distalsection 82 in the general directions 83 and 84. The deployment mechanism63 may comprise any one of a number of suitable devices adapted toprovide reciprocating motion. These may be manually or electronicallyactuated. For example, a spring-loaded plunger mechanism may be utilizedto provide forward and backward motion to the piercing member distalsection 82. Any one of a number of suitable actuators, for example, asolenoid actuator may be utilized to operate the deployment mechanism ordevice 63.

[0114] In the illustrated embodiment of FIGS. 7A-7D, the stent-deliverymechanism 64 generally comprises a plurality of elongated rods, membersor elements 65 with distal ends or sections 66. The stent-deliverymechanism 64 is moveably located or mounted within the lumen 60 of theapplicator 56. The stent-delivery elements 65 can be moved forwardly (inthe general direction of arrow 83) and backwardly (in the generaldirection of arrow 84) by a suitable deployment mechanism. Thedeployment mechanism may comprise any one of a number of suitabledevices adapted to provide reciprocating motion. These may be manuallyor electronically actuated. For example, a spring-loaded plungermechanism may be utilized to provide forward and backward motion to thestent-delivery elements 65. Any one of a number of suitable actuators,for example, a solenoid actuator may be utilized to operate thestent-delivery mechanism or device 64.

[0115]7A illustrates a first step of delivering the stent implant 31 byholding the stent 31 inside the lumen 60 of the applicator or applicatorportion 61. During the delivery stage, the applicator 56 as shown inFIG. 7A is introduced through a small incision on the cornea or sclerawall of the eye. The small incision may be less than about 1 mm in sizeand designated as “Sub one” incision. In one embodiment, the distal end71 of the applicator 56 approaches the trabecular meshwork 21 on theopposite side of the small incision when a generally straight orslightly curved applicator is utilized (as discussed below in connectionwith FIG. 9). In another embodiment, the distal end 71 of the applicator56 approaches the trabecular meshwork 21 on the same side of the smallincision when a generally curved applicator is utilized.

[0116]FIG. 7B illustrates a second step of delivering the stent implant31 by creating an opening in the trabecular meshwork 21 using thepiercing member 62. (The piercing tip 61 or the piercing member 62 ingeneral may comprise mechanical or energy-assisted piercingcapabilities, as disclosed above.) The deployment mechanism 63 isactuated and the piercing member distal section 82 and piercing tip 61are advanced in the forward direction 83. In the illustrated embodiment,the piercing member distal section 82 and piercing tip 61 travel throughthe stent lumen 34 and out of the lumen 60 through the lumen orifice 56to engage the trabecular meshwork 21. The piercing step may compriseeither partially piercing into the trabecular meshwork 21 or completelypiercing through the trabecular meshwork 21 to facilitate the stentinsertion in the trabecular bypass surgery disclosed herein. The lengthof the piercing member distal section 82 is sized for adequate piercingwithout causing damage or injury to the backside or rear of Schlemm'scanal 22.

[0117]FIG. 7C illustrates a third step of delivering the stent implant31 by retracting the piercing member distal section 82 into the lumen 60of the applicator 56. The deployment mechanism 63 is actuated and thepiercing member distal section 82 and piercing tip 61 are retracted inthe backward direction 84. In the illustrated embodiment, the piercingmember distal section 82 and piercing tip 61 travel the lumen orifice 56and the stent lumen 34 and into the lumen 60. FIG. 7C also illustratesthe actuation of the stent-delivery mechanism 64 and the advancement ofthe delivery elements 65 through the guidance or alignment holes 43 inthe forward direction 83.

[0118] In some embodiments, the step of retracting the piercing member62 (and piercing member distal section 82) as shown in FIG. 7C may bedelayed or modified. This would allow guidance of the stent delivery sothat the stent 31 may be advanced along and within the guidingenvironment of the piercing member 62 when the piercing member distalsection 82 is still extended out of the distal point 71 of theapplicator 56 and through the stent lumen 34. Thus, undesirable movementof the stent 31 is advantageously restricted or substantiallyeliminated.

[0119]FIG. 7D illustrates a fourth step of delivering the stent implant31 by inserting the stent 31 through the opening (or partial or fullincision) created in the trabecular meshwork 21 by the piercing member62. In the illustrated embodiment, preferably immediately afterretraction of the piercing member 62, the stent delivery mechanism 64 isactivated by advancing the delivery elements 65 through the throughputholes 43 in the forward direction 83. The throughput holes 43 are usedto guide the delivery elements 65 for effective stent delivery into theopening of the trabecular meshwork 21. The distal ends 66 contact orabut against the stent upper section 30 and guide the stent 31 into theopening (or incision) created in the trabecular meshwork 21. In theillustrated embodiment, the stent 31 travels out of the lumen 60 throughthe lumen orifice 56 to engage the trabecular meshwork 21. Once thestent has been implanted, the delivery elements 65 are retracted in thebackward direction 84.

[0120] Some aspects of the invention provide an applicator for placing atrabecular stent into trabecular meshwork. The applicator generallycomprises a sheath for holding the trabecular stent within a lumen ofthe sheath. The trabecular stent generally comprises an inlet section,an outlet section and a lumen extending from the inlet section to theoutlet section. The applicator includes a piercing member located withinthe sheath, wherein the piercing member is slidably moveable through thelumen of the trabecular stent for creating an opening at about thetrabecular meshwork. The applicator further includes a stent deliverymechanism for delivering the stent through the opening. The stent mayfurther comprise a middle section between the inlet section and theoutlet section, wherein the circumference of the middle section issmaller than the circumference of the inlet section.

[0121]FIG. 9 illustrates a method for placing the stent implant 31 orother suitable stent device at the implant site. In the illustratedembodiment, the stent-delivery applicator or applicator portion 56 isincorporated into an irrigating or irrigation apparatus or device 51.The apparatus 51 generally comprises a syringe portion 54 and a cannulaportion 55 and/or the applicator portion 56. The distal section of thecannula portion 55 may have at least one irrigating hole 53. Theapplicator 56 or the applicator portion is used to hold and implant thestent 31 using the piercing member 62 (including the deploymentmechanism 63) and the stent delivery mechanism 64, as described above inconnection with FIGS. 7A-7D. The proximal end 57 of the lumen 60 of thedistal applicator portion 56 may be sealed from the remaining lumen ofthe cannula portion 55 to prevent fluid leakage.

[0122] In an exemplary embodiment of the trabecular meshwork surgery,the patient is placed in the supine position, prepped, draped andadministered anesthesia. In one embodiment, a small (less than 1 mm in a“Sub one” surgery) self-sealing incision 52 (FIG. 9) is made in thecornea 12 opposite the stent placement site. The stent-loaded applicator56 is advanced through the corneal incision 52 across the anteriorchamber 20 held in the irrigating apparatus 51 under gonioscopic (lens)or endoscopic guidance, as illustrated in FIG. 9. The applicator 56 isused to make an incision in the trabecular meshwork 21 and implant thestent 31, as described in detail above, advantageously, in a one-stepprocedure. The irrigating apparatus 51 and the applicator 56 (withoutthe stent) are withdrawn from the eye 10 and the surgery concluded.

[0123] Some aspects provide a method for inserting a trabecular stentthrough trabecular meshwork comprising: holding the trabecular stentwithin a lumen of an applicator, wherein the applicator comprises aslidably moveable piercing member located within the lumen of theapplicator; delivering the applicator to about a surface of thetrabecular meshwork; advancing the piercing member through a lumen ofthe trabecular stent for creating an opening at the trabecular meshwork;and inserting the trabecular stent into the opening. In one embodiment,the step of delivering the applicator is carried out by passing througha small incision at a cornea of an eye, wherein the small incision couldbe less than one millimeter in size.

[0124] Some aspects provide a device and a method for clearing theobstructed lumen of a trabecular stent in an ab interno procedure. Aftera stent has been implanted at about the trabecular meshwork with oneopening of the device exposed to the anterior chamber and the otheropening of the device exposed to Schlemm's canal, the lumen of thetrabecular stent may be obstructed, plugged or partially blocked withdiminished aqueous transportation ability.

[0125] A repairing applicator 96 as shown in FIG. 10 may be used torestore the aqueous transmission function through the implantedtrabecular stent 31 or other plugged stent. The repairing applicator 96generally comprises a generally cylindrical outer housing, cover orsheath 110, a lumen or passage 90, a piercing member, device ormechanism 92. The applicator or applicator portion 96 has an opening ororifice 111 at a distal-most end 101.

[0126] In the illustrated embodiment of FIG. 10, the piercing member 92is axially moveable within the lumen 90 of the applicator 96. Thepiercing member 92 generally comprises a distal section 112 having adistal end or piercing tip 91, a medial body portion or section 97 and aproximal deployment section or mechanism 93. The piercing member 92 ismoveably located or mounted within the lumen 90 of the applicator 96.The piercing member distal section 112, distal end 91 along with thebody 97 can be moved forwardly (in the general direction of arrow 113)and backwardly (in the general direction of arrow 114) by the deploymentmechanism 93 inside the lumen 90 of the applicator 96.

[0127] The piercing member distal end 91 (FIG. 10) is sized andconfigured to effectively clear any obstruction inside the opening orlumen of an implanted stent. To help guide and support the piercingmember 92, a supporter or support element 73 with a concentric hole 75at its center sized for allowing the piercing member distal section 112and distal end 91 to easily pass through is secured at a proper luminallocation of a distal section 116 of the repairing applicator 96.

[0128] In accordance with one aspect, the means or device for clearingthe obstruction inside the opening or lumen of an implanted stent maycomprise a microknife, a pointed guidewire, a sharpened trephine, ascrew shaped trephine, an irrigating tubing, a retinal pick, amicrocurrette, or the like. In accordance with another aspect, theobstruction may be cleared with an energy-assisted device, such as alaser optic fiber, a radiofrequency (RF) electrode, an ultrasonictransducer, a microwave antenna, a heated or cooled instrument or thelike. Fiberoptic lasers that are suitable for such use include, forexample, Q-switched Neodymiun (Nd):YAG lasers, Erbium:YAG lasers, coldCO₂ lasers and the like.

[0129] In the illustrated embodiment of FIG. 10, the deploymentmechanism 93 provides for the movement of the piercing member distalsection 112 in the general directions 113 and 114. The deploymentmechanism 93 may comprise any one of a number of suitable devicesadapted to provide reciprocating motion. These may be manually orelectronically actuated. For example, a spring-loaded plunger mechanismmay be utilized to provide forward and backward motion to the piercingmember distal section 112. Any one of a number of suitable actuators,for example, a solenoid actuator may be utilized to operate thedeployment mechanism or device 93.

[0130] Some aspects provide a repairing applicator for clearing anobstructed lumen of an implanted trabecular stent. The repairingapplicator generally comprises a sheath and a piercing member locatedwithin the sheath, wherein the piercing member is slidably moveableapproaching the obstructed lumen of the implanted trabecular stentconfigured for clearing the lumen.

[0131] From the foregoing description, it will be appreciated that anovel approach for the surgical treatment of glaucoma has been disclosedfor releasing excessive intraocular pressure. While the components,techniques and aspects of the invention have been described with acertain degree of particularity, it is manifest that many changes may bemade in the specific designs, constructions and methodology herein abovedescribed without departing from the spirit and scope of thisdisclosure.

[0132] Various modifications and applications of the invention may occurto those who are skilled in the art, without departing from the truespirit or scope of the invention. It should be understood that theinvention is not limited to the embodiments set forth herein forpurposes of exemplification, but is to be defined only by a fair readingof the appended claims, including the full range of equivalency to whicheach element thereof is entitled.

What is claimed is:
 1. A method for inserting a trabecular stent througha trabecular meshwork of an eye, the method comprising: retaining thetrabecular stent within a lumen of an applicator, wherein the applicatorcomprises a slidably movable piercing member located within the lumen ofthe applicator; delivering the applicator to about a surface of thetrabecular meshwork; advancing the piercing member through a lumen ofthe trabecular stent for creating an opening at the trabecular meshwork;and inserting said trabecular stent into said opening.
 2. The method ofclaim 1, wherein the delivering of the applicator occurs through anincision at a cornea of the eye.
 3. The method of claim 1, wherein theincision is less than one millimeter in size.
 4. The method of claim 1,wherein the trabecular stent comprises an inlet section and an outletsection, and the inserting further comprises placing the inlet sectionat least partially inside an anterior chamber of the eye and the outletsection at least partially inside Schlemm's canal of the eye.
 5. Themethod of claim 1, wherein the piercing member comprises a knife or apointed guide member.
 6. The method of claim 1, wherein the piercingmember comprises a laser probe.
 7. The method of claim 1, wherein thepiercing member comprises an energyassisted piercing member.
 8. Themethod of claim 7, wherein the energy-assisted piercing member comprisesa radiofrequency transmitter.
 9. The method of claim 7, wherein theenergy-assisted piercing member comprises an optic fiber.
 10. The methodof claim 7, wherein the energy-assisted piercing member comprises amicrowave antenna.
 11. The method of claim 7, wherein theenergy-assisted piercing member comprises an ultrasound transducer. 12.An applicator for placing a trabecular stent into a trabecular meshworkof an eye, the applicator comprising: a sheath for holding thetrabecular stent within a lumen of the sheath; a piercing member locatedwithin said sheath, wherein the piercing member is slidably movablethrough a lumen in the trabecular stent for creating an opening at aboutthe trabecular meshwork; and a stent delivery mechanism for deliveringsaid stent through said opening.
 13. The applicator of claim 12, whereinthe piercing member comprises a knife or a pointed guide member.
 14. Theapplicator of claim 12, wherein the piercing member comprises a laserprobe.
 15. The applicator of claim 12, wherein the piercing membercomprises an energy-assisted piercing member.
 16. The applicator ofclaim 15, wherein the energy-assisted piercing member comprises aradiofrequency transmitter.
 17. The applicator of claim 15, wherein theenergy-assisted piercing member comprises an optic fiber.
 18. Theapplicator of claim 15, wherein the energy-assisted piercing membercomprises a microwave antenna.
 19. The applicator of claim 15, whereinthe energy-assisted piercing member comprises an ultrasound transducer.20. An applicator for clearing an obstructed lumen of an implantedtrabecular stent, the applicator comprising: a sheath; and a piercingmember located within said sheath, wherein the piercing member isslidably movable toward the obstructed lumen of the implanted trabecularstent and is configured for clearing said lumen.
 21. The applicator ofclaim 20, wherein the piercing member comprises a knife or a pointedguide member.
 22. The applicator of claim 21, wherein the piercingmember comprises a laser probe.
 23. The applicator of claim 21, whereinthe piercing member comprises an energy-assisted piercing member. 24.The applicator of claim 23, wherein the energy-assisted piercing membercomprises a radiofrequency transmitter.
 25. The applicator of claim 23,wherein the energy-assisted piercing member comprises an optic fiber.26. The applicator of claim 23, wherein the energy-assisted piercingmember comprises a microwave antenna.
 27. The applicator of claim 23,wherein the energy-assisted piercing member comprises an ultrasoundtransducer.
 28. A method of creating an opening at a trabecular meshworkfor implanting a stent into the trabecular meshwork comprising advancinga piercing member through a lumen of the stent for creating the openingat said trabecular meshwork.